{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-64450", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-64450", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-07-25T08:51:20.319Z", "updatedAt": "2026-10-19T20:38:30.286Z", "importedAt": "2026-10-24T01:58:25.636Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "tipc: fix out-of-bounds read in broadcast Gap ACK blocks", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix out-of-bounds read in broadcast Gap ACK blocks\n\nA broadcast PROTOCOL/STATE_MSG can carry a Gap ACK blocks record in its\ndata area. tipc_get_gap_ack_blks() only verifies that the record's len\nfield is self-consistent with its ugack_cnt/bgack_cnt counts\n(sz == struct_size(p, gacks, ugack_cnt + bgack_cnt)); it does not check\nthat the record actually fits in the message data area, msg_data_sz().\n\nThe unicast caller tipc_link_proto_rcv() bounds it (\"if (glen > dlen)\nbreak;\"), but the broadcast caller tipc_bcast_sync_rcv() discards the\nreturned size, so tipc_link_advance_transmq() copies the record off the\nreceive skb with an attacker-controlled count:\n\n\tthis_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),\n\t\t\t GFP_ATOMIC);\n\nA TIPC neighbour that negotiated TIPC_GAP_ACK_BLOCK triggers it with one\nordinary broadcast STATE_MSG (msg_bc_ack_invalid() clear), sized so its\ndata area is short, carrying a Gap ACK record with len = 0x400,\nbgack_cnt = 0xff and ugack_cnt = 0. len then equals\nstruct_size(p, gacks, 255), so the consistency check passes and ga is\nnon-NULL; kmemdup() reads struct_size(ga, gacks, 255) = 1024 bytes out\nof the much smaller skb:\n\n BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x48/0x60\n Read of size 1024 at addr ffff0000c7030d38 by task poc864/69\n Call trace:\n kmemdup_noprof+0x48/0x60\n tipc_link_advance_transmq+0x86c/0xb80\n tipc_link_bc_ack_rcv+0x19c/0x1e0\n tipc_bcast_sync_rcv+0x1c4/0x2c4\n tipc_rcv+0x85c/0x1340\n tipc_l2_rcv_msg+0xac/0x104\n The buggy address belongs to the object at ffff0000c7030d00\n which belongs to the cache skbuff_small_head of size 704\n The buggy address is located 56 bytes inside of\n allocated 704-byte region [ffff0000c7030d00, ffff0000c7030fc0)\n\nThe copied-out bytes are subsequently consumed as gap/ack values, but\nthe read is already out of bounds at the kmemdup() regardless of how\nthey are used.\n\nThe unicast STATE path drops such a message: \"if (glen > dlen) break;\"\nskips the rest of STATE_MSG handling and the skb is freed. Make the\nbroadcast path drop it too. tipc_bcast_sync_rcv() now bounds the record\nagainst msg_data_sz() and, when it does not fit, reports it back through\ntipc_node_bc_sync_rcv() to tipc_rcv() so the skb is discarded rather than\nprocessed. ga is not cleared on this path: ga == NULL already means\n\"legacy peer without Selective ACK\", a distinct legitimate state.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "055663d21dc4336f67933ab26bef3c5934be6324" }, { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "016f5995c37a5a2c45198308f830f244517d70b7" }, { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "74b45af86a767594ba52330cd440ea84e24d700d" }, { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "9a51115fcdc78687c8852bf93a1db3951dbb223b" }, { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "a21ed5064217cc33726da6c7ef1a520eba43aea1" }, { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "2de42e268174766cb2e2b90721afdfdff70e0d8d" }, { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "f333b6851bdf326fd2134133272dbbed0c94d921" }, { "version": "d7626b5acff9227e2a65da636a53e09bdafdc0aa", "status": "affected", "versionType": "git", "lessThan": "2b66974a1b6134a4bbc3bfed181f7418f688eb54" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.8", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.8" }, { "version": "5.10.261", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.212", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.178", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.145", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.96", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.39", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.1.4", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.1.*" }, { "version": "7.2", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }